/*
 * Copyright (c) 2007, 2021, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package com.sun.org.apache.bcel.internal.util;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache BCEL" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache BCEL", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import jdk.xml.internal.SecuritySupport;

import java.util.*;
import java.util.zip.*;
import java.io.*;

/**
 * Responsible for loading (class) files from the CLASSPATH. Inspired by
 * sun.tools.ClassPath.
 *
 * @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
 * @version $Id: ClassPath.java,v 1.4 2007-07-19 04:34:52 ofung Exp $
 */
public class ClassPath implements Serializable {
    public static final ClassPath SYSTEM_CLASS_PATH = new ClassPath();

    private PathEntry[] paths;
    private String class_path;

    /**
     * Search for classes in given path.
     */
    public ClassPath(String class_path) {
        this.class_path = class_path;

        ArrayList vec = new ArrayList();

        for (StringTokenizer tok = new StringTokenizer(class_path,
                SecuritySupport.getSystemProperty("path.separator"));
             tok.hasMoreTokens(); ) {
            String path = tok.nextToken();

            if (!path.equals("")) {
                File file = new File(path);

                try {
                    if (SecuritySupport.isFileExists(file)) {
                        if (file.isDirectory())
                            vec.add(new Dir(path));
                        else
                            vec.add(new Zip(new ZipFile(file)));
                    }
                } catch (IOException e) {
                    System.err.println("CLASSPATH component " + file + ": " + e);
                }
            }
        }

        paths = new PathEntry[vec.size()];
        vec.toArray(paths);
    }

    /**
     * Search for classes in CLASSPATH.
     *
     * @deprecated Use SYSTEM_CLASS_PATH constant
     */
    public ClassPath() {
        // this(getClassPath());
        this("");
    }

    /**
     * @return used class path string
     */
    public String toString() {
        return class_path;
    }

    public int hashCode() {
        return class_path.hashCode();
    }

    public boolean equals(Object o) {
        if (o instanceof ClassPath) {
            return class_path.equals(((ClassPath) o).class_path);
        }

        return false;
    }

    private static final void getPathComponents(String path, ArrayList list) {
        if (path != null) {
            StringTokenizer tok = new StringTokenizer(path, File.pathSeparator);

            while (tok.hasMoreTokens()) {
                String name = tok.nextToken();
                File file = new File(name);

                if (SecuritySupport.isFileExists(file)) {
                    list.add(name);
                }
            }
        }
    }

    /**
     * Checks for class path components in the following properties:
     * "java.class.path", "sun.boot.class.path", "java.ext.dirs"
     *
     * @return class path as used by default by BCEL
     */
    public static final String getClassPath() {

        String class_path, boot_path, ext_path;

        try {
            class_path = SecuritySupport.getSystemProperty("java.class.path");
            boot_path = SecuritySupport.getSystemProperty("sun.boot.class.path");
            ext_path = SecuritySupport.getSystemProperty("java.ext.dirs");
        } catch (SecurityException e) {
            return "";
        }

        ArrayList list = new ArrayList();

        getPathComponents(class_path, list);
        getPathComponents(boot_path, list);

        ArrayList dirs = new ArrayList();
        getPathComponents(ext_path, dirs);

        for (Iterator e = dirs.iterator(); e.hasNext(); ) {
            File ext_dir = new File((String) e.next());
            String[] extensions = SecuritySupport.getFileList(ext_dir, new FilenameFilter() {
                public boolean accept(File dir, String name) {
                    name = name.toLowerCase();
                    return name.endsWith(".zip") || name.endsWith(".jar");
                }
            });

            if (extensions != null)
                for (int i = 0; i < extensions.length; i++)
                    list.add(ext_path + File.separatorChar + extensions[i]);
        }

        StringBuffer buf = new StringBuffer();

        for (Iterator e = list.iterator(); e.hasNext(); ) {
            buf.append((String) e.next());

            if (e.hasNext())
                buf.append(File.pathSeparatorChar);
        }

        return buf.toString().intern();
    }

    /**
     * @param name fully qualified class name, e.g. java.lang.String
     * @return input stream for class
     */
    public InputStream getInputStream(String name) throws IOException {
        return getInputStream(name, ".class");
    }

    /**
     * Return stream for class or resource on CLASSPATH.
     *
     * @param name   fully qualified file name, e.g. java/lang/String
     * @param suffix file name ends with suff, e.g. .java
     * @return input stream for file on class path
     */
    public InputStream getInputStream(String name, String suffix) throws IOException {
        InputStream is = null;

        try {
            is = getClass().getClassLoader().getResourceAsStream(name + suffix);
        } catch (Exception e) {
        }

        if (is != null)
            return is;

        return getClassFile(name, suffix).getInputStream();
    }

    /**
     * @param name   fully qualified file name, e.g. java/lang/String
     * @param suffix file name ends with suff, e.g. .java
     * @return class file for the java class
     */
    public ClassFile getClassFile(String name, String suffix) throws IOException {
        for (int i = 0; i < paths.length; i++) {
            ClassFile cf;

            if ((cf = paths[i].getClassFile(name, suffix)) != null)
                return cf;
        }

        throw new IOException("Couldn't find: " + name + suffix);
    }

    /**
     * @param name fully qualified class name, e.g. java.lang.String
     * @return input stream for class
     */
    public ClassFile getClassFile(String name) throws IOException {
        return getClassFile(name, ".class");
    }

    /**
     * @param name   fully qualified file name, e.g. java/lang/String
     * @param suffix file name ends with suffix, e.g. .java
     * @return byte array for file on class path
     */
    public byte[] getBytes(String name, String suffix) throws IOException {
        InputStream is = getInputStream(name, suffix);

        if (is == null)
            throw new IOException("Couldn't find: " + name + suffix);

        DataInputStream dis = new DataInputStream(is);
        byte[] bytes = new byte[is.available()];
        dis.readFully(bytes);
        dis.close();
        is.close();

        return bytes;
    }

    /**
     * @return byte array for class
     */
    public byte[] getBytes(String name) throws IOException {
        return getBytes(name, ".class");
    }

    /**
     * @param name name of file to search for, e.g. java/lang/String.java
     * @return full (canonical) path for file
     */
    public String getPath(String name) throws IOException {
        int index = name.lastIndexOf('.');
        String suffix = "";

        if (index > 0) {
            suffix = name.substring(index);
            name = name.substring(0, index);
        }

        return getPath(name, suffix);
    }

    /**
     * @param name   name of file to search for, e.g. java/lang/String
     * @param suffix file name suffix, e.g. .java
     * @return full (canonical) path for file, if it exists
     */
    public String getPath(String name, String suffix) throws IOException {
        return getClassFile(name, suffix).getPath();
    }

    private static abstract class PathEntry implements Serializable {
        abstract ClassFile getClassFile(String name, String suffix) throws IOException;
    }

    /**
     * Contains information about file/ZIP entry of the Java class.
     */
    public interface ClassFile {
        /**
         * @return input stream for class file.
         */
        public abstract InputStream getInputStream() throws IOException;

        /**
         * @return canonical path to class file.
         */
        public abstract String getPath();

        /**
         * @return base path of found class, i.e. class is contained relative
         * to that path, which may either denote a directory, or zip file
         */
        public abstract String getBase();

        /**
         * @return modification time of class file.
         */
        public abstract long getTime();

        /**
         * @return size of class file.
         */
        public abstract long getSize();
    }

    private static class Dir extends PathEntry {
        private String dir;

        Dir(String d) {
            dir = d;
        }

        ClassFile getClassFile(String name, String suffix) throws IOException {
            final File file = new File(dir + File.separatorChar +
                    name.replace('.', File.separatorChar) + suffix);

            return SecuritySupport.isFileExists(file) ? new ClassFile() {
                public InputStream getInputStream() throws IOException {
                    return new FileInputStream(file);
                }

                public String getPath() {
                    try {
                        return file.getCanonicalPath();
                    } catch (IOException e) {
                        return null;
                    }

                }

                public long getTime() {
                    return file.lastModified();
                }

                public long getSize() {
                    return file.length();
                }

                public String getBase() {
                    return dir;
                }

            } : null;
        }

        public String toString() {
            return dir;
        }
    }

    private static class Zip extends PathEntry {
        private ZipFile zip;

        Zip(ZipFile z) {
            zip = z;
        }

        ClassFile getClassFile(String name, String suffix) throws IOException {
            final ZipEntry entry = zip.getEntry(name.replace('.', '/') + suffix);

            return (entry != null) ? new ClassFile() {
                public InputStream getInputStream() throws IOException {
                    return zip.getInputStream(entry);
                }

                public String getPath() {
                    return entry.toString();
                }

                public long getTime() {
                    return entry.getTime();
                }

                public long getSize() {
                    return entry.getSize();
                }

                public String getBase() {
                    return zip.getName();
                }
            } : null;
        }
    }
}
